Marginalization is treating an individual, a group of people, or a concept as unimportant. This often pertains to the exclusion of a subgroup by not equitably attending to their needs or goals. It is usually concerned with economic, political, religious, gender-related and well-being opportunities.
For instance, a minority group such as the elderly is marginalized regarding career opportunities; several companies do not rehire those who are aged 50 even if they are still capable of performing the job description. Another example is when an individual is not allowed to run for a political office just because she is a female.